Several tragic accidents over the years have emphasized the need for an airborne collision avoidance system. Notable among these were the collision of two Boeing 747 type aircraft on the airport runway at Santa Cruz de Tenerife, Canary Islands and the mid-air collision of a scheduled airliner with a training airplane over the city of San Diego, Calif. The Tenerife accident occurred on 27 Mar. 1977 and claimed 582 lives. The San Diego collision toll was 144 lives including seven persons on the ground, occurring on 25 Sept. 1978. More recently, two commercial sight-seeing aircraft, operating under visual flight rules, collided over the Grand Canyon in June of 1986 with 26 lives being lost.
The steady increase in air traffic which continues to this time make such accidents an ever present danger. Various sources have reported the number of near-miss incidents each year as numbering in the hundreds. While the precise number of these occurrences are in some dispute all parties are agreed that the hazard is real and that urgent action is required to attain a more safe environment for the air traveler.
Efforts to achieve a greater degree of air safety have been made with some measure of success. Most effective have been those measures which have improved the precision and response times of air traffic control equipment in the air terminal locality. For obvious reasons, the air traffic density is high in such areas making close approaches a matter of necessity. Methods of improving the human factors considerations of air control have also been stressed. Generally, these relate to improved working conditions, adequate rest periods and similar actions to ease the physical and mental burdens of air control operators.
The aircraft pilot bears ultimate responsibility for the safety of his flight and to date has received little in the way of an efficient and economical monitoring system which could warn of impending danger. Various proposals have been made but have failed to generate an enthusiastic endorsement in the aviation community. Perhaps cost is the greatest cause of this lack as most general aviation operators do not have the resources to expend on expensive and complex warning systems. Another factor involved is complexity. The aircraft cockpit is currently complicated by a multiplicity of indicators related to flight operation and safety. Any new display must be compact, germane and non-ambiguous to gain entry to this arena.
The Telemetry Burst Collision Avoidance System (TBCAS) of the present invention is capable of warning the pilot of impending collision with another aircraft, a runway maintenance vehicle or a mountain peak. It performs this function automatically without recourse to the information held in the air traffic control center and thus permits the pilot to monitor directly the adequacy of specific guidance received from that center. Conversely, it permits a suitably equipped air traffic control center to monitor the performance of other sensor equipment, principally radars, and of pilot response to flight recommendations. It accomplishes this using airborne equipment approximating the complexity of a citizen-band radio transceiver and a personal computer. The cost of the complete system for each aircraft, runway maintenance vehicle or ground obstruction should not exceed two thousands dollars. TBCAS depends upon each station, either ground or air, having a precise record of its current geographic location in world wide coordinates of latitude and longitude. The primary source for this data is expected to be the Global Positioning System, although provision is made for use of alternate sources such as TACAN, LORAN or other radionavigation aids and for dead-reckoning calculations.